Testing apparatus



March 23, 1937; M. M.- CUNNINGHAM TESTING APPARATUS Filed July 9, 1954 4 Sheeis-Sheet 1 Qua ,4 /4

INVENTOR. Mae/01v M Cum/wane! 1 ATTORNEY.

March 23, 1937. M. M. CUNNINGHAM 2,074,372

TESTING APPARATUS Filed July 9, 1954 4 Sheets-Sheet 2 i INVENTOR.

s Mee/oA/MCWN/A/cwaM Y BY ATTORNEY.

. March 23, 1937. M. M. CUNNINGHAM 7 TESTING- APPARATUS Filed July 9, 1954 4 Sheets-Sheet 4 ATTORNEY.

- Patented Mai. 23, 1937 UNITED STATES PATENT OFFICE f 2,074,372 TESTING APPARATUS Marion M. Cunningham, South Bend, Ind., as-

signor .to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application July 9', 1934., Serial ri -734.396

' 9 Claims. (01. 265-25) ering the fuselage to convenient loading height." More particularly the invention has .to do with a novel form of brake testing device supported upon a hydraulic lift, which brake testing device may also be employed as an anchor against movement of the plane during motor testing and which hydraulic lift may be used to weigh the plane and lower the same so that the fuselage will be at a convenient loading height and horizontal.

An object of the invention is to provide a novel brake testing unit employing a shell having an internal annular continuous track adapted to receive a vehicle, wheel, together with mechanism for conveniently permitting a vehicle wheel to be placed therewithin for the purpose of being tested while within the shell, the rotation of the shell im" parting rotation to the wheeL,

Another object of the invention is to provide in combination with a substantially cylindrical internal track, means for driving the track against the resistance of a wheel brake.

A further object of the invention is to provide means for readily permitting the placing of the wheels of a vehicle within the internal drum track.

The above and other novel features of the inf vention will appear more fully hereinafter from the following detailed description when taken in conjunction with the accompanying drawings. It is expressly understood, however, that the drawingsdare for purposes of illustration only and are not designed as a definition of the invention,

reference being had for this purpose to the appended claims,

In the drawings wherein like reference characters indicate like parts:

Fig. 1 is a side elevation partly in section show-,. ing the hydraulic lift and brake testingunits and an airplane supported thereby;

Fig. 2 is'a top plan view of the lift illustrating the brake testing drums set at an angle for access thereinto and shown partly in section;

Fig. 3 is a rear elevation of the lift and brake testing units, the hydraulic cylinder being shown in section and is taken generally on the line 3-3 of Fig. 9.; r

Fig. 4 is a top plan view illustrating in detail .the brake testing unit and its driving mechanism;

-- Fig. 5 is a side elevation of Fig. 4 generally head ill] of taken on the line 5-5 of Fig. 4, certain parts thereof being shown in section;'

1-1, and

Fig. 8 is a section of amodified form of test; ing unit employing an internal conical tread. V

Fig. '7 is a section f Fig. 6' taken on the line F g. 6 is a section of Fig. 4 taken on thefline Referring more particularly to Fig. 1 there is shown therein the level surface 20 of, for example, an aviation landing field, an airplane body 22, a landing get; 24 and tail wheel 26. -In an excavation generally" indicated by '30 there is.-

inserted a hydraulic lift having a cylinder 32 and piston 34 with'usu'al stufling glands 36 to prevent leakage of the fluid employed in operating the: lift. A supply pipe line 38'having a valvular ontrol '40 and a pressure indicating gauge 42 is connected to the cylinder and through which pipe line fluid is forced into the cylinder or ejected therefrom. Secured on the top of the piston 34 for movement therewith area pair of horizontal transverse channel members 44 and 46 which are adapted to support adjacent their ends a pair of wheel supports generally indicated as 48 and 50. The end of the channel members 44 and 46 are adapted to engage the vertical tracks52 and 54 set in the'side of the excavated cavity 30 and which tracks are adapted to steady the lift in its upward and downward movement and 9.150 to.

resist any tendency of the lift to turn as a res'ult As illustrated in Figs. 2 to 7, the wheel support- ,0 of unequalized brakes as will appeanhereinafter.

ing means 48 and eachcomprise a support block or base 56 rigidly secured to the channel members 44 and 46 and which blocks are. adapted throughtrunnions 58 to swivelly support a wheel tread Ell-and revoluble internal drum or shell 62, and

anti-friction bearings 59 are preferably employed to support the load and ease the turning of-. the wheel support .50.

As illustrated in Fig. 2, the wheel treads and revoluble drums are swivelly arranged for the v purpose of permitting the wheels 64 of an airplane to enter and' to be enclosed therein. For

lock is provided which is constituted by a pin 66 slidable vertically in apertures 12 and 14 formed in transverse members 68 and-l0 secured across and between the channel members 44 and 46. A

spring Hiacting against a shoulder 18 on the pin v 66 is adapted to urge the same upward and the ill the pin is adapted to received .in-

any one of the three pockets 82, 94 and 86 provided in the underside of the tread plate 60. To release the pin to permit swivelling of the revoluble drum and wheel tread 'to various positions illustrated, a knob 88 conveniently arranged to be operated by the foot is secured to the rod on pin 66 so that the same may be pushed downward and withdrawn from the pockets 82, 84, and 86 provided in the underside of the plate 66. Suitablerunways 90 and 92 are provided so that the vehicle may be rolled onto the support drum Plates and into the units.

To test the brakes, means are provided for rotating each of the drums individually and for this purpose there is shown an electric motor 94 geared to a shaft 86 which carries the worm 98, which, in turn, is adapted to drive a worm wheel I secured to the shaft I02 which carries the driving torque to the rotatable drum shell 62.

In order to test the efliciency of the brakes, torque measuring means are provided which measures the thrust imposed upon the worm 68 while transmitting its force to the worm wheel I00. For this purpose the shaft 96 is permitted to'move a certain amount longitudinally upon its axis and for this purpose the pinion I64 is provided with considerable length so that its meshing gear I08 may move longitudinally through without becoming disengaged.

The thrust of the shaft 96 is resisted by a cylinder H4 and piston III! which are connected to a gauge II6 which is adapted to indicate the pressure therein and in order to transmit the thrust to the piston I I0 free of the turning movement of the shaft 96, a thrust bearing I I2 is provided at the end of the shaft 96, the thrust bearing being adapted to transmit thrust only to the piston III] and compress or place the fluid within the cylinder II4 under compression.

The revoluble drum 62, which may have its inner surface knurled to prevent slippage to promote traction between the vehicle wheel and the inner surface, is preferably supported upon a pair of rollers I26 and I22 mounted on short shafts I24 and I26 carried in the tread plate 60 as best illustrated in Fig. 6. The use of the support rollers in this manner relieves the shaft I62 from the weight of the vehicle and generally aids in providing an adequate eflicient structure for the purpose desired.

Referring to the modification of Fig. 8 it will the shell may be driven by a worm wheel I62 and worm I64 and a shaft I66 which may be driven by a motor in a similar fashion to Fig. and the thrust of the shaft I66 may be absorbed and measured by a cylinder and piston I68 connected to a gauge I10.

The use of the device will be clearly apparent from the foregoing description. For example, the front wheels of the carriage of a plane may be driven into the shells 62 While the same are set at an angle as illustrated in Fig. 2. Thereafter, the shells are turned parallel so that the axis corresponds substantially to the wheel axis or at least lie in substantially the samejvertical plane,

and thereafter the brakes of the airplane may be tested by rotating the shells against the resistance of the wheel brakes and measuring the thrust pressures on each of the gauges I66. After a test of the brakes, the motors of the plane may be tested, it being unnecessary for this test to anchor the plane since the wheels are retained within the shell 62 and are prevented from moving as a result of. the thrust imposed upon the plane by the propeller during the testing operation.

In order to safeguard against lowering of the lift during test due to leakage or loss of the pressure in the hydraulic lift cylinder 34, it has been found desirable to supply the channel member 46 with a setof spring pressed manually releasable pins I48 which are adapted to engage apertures I44 in the guide members 52 and 54 which apertures may be placed at a plurality of convenient or suitable points in the guide members.

While the plane is supported upon the lift, the same may be weighed by releasing the pins I48 thus indicating on the gauge 42 the hydraulic pressure within the cylinder 32 necessary to lift or sustain the forward end of the plane, and the weight of the plane may be measured both with the plane lifted to a three pointed landing position or with the plane in the position as shown in Fig. 1, its normal flying aspect, or any desired intermediate position. It will be apparent, of course, that the weight upon the tail wheel 26 is generally light and is often negligible in considering the load weight of a plane but the weight resting upon the tail wheel may be measured by any suitable means if so desired, toobtain the overall weight.

It will thus appear that there is provided a novel mechanism for use on landing fields in conjunction with airplanes and that the use thereof enables the testing of the plane and its equipment, the Weighing of the plane and also facilitates loading of the plane since the same may be loaded in a position in which the fuselage is adjacent to and horizontal with the ground surface. It will, of course, be appreciated that loading of a plane is facilitated when the same is in the position shown in Fig. 1 or its normal flying aspect.

I Only two embodiments of the invention have been illustrated and described in the combination, and it is to be understood that the invention is not limited thereto but may be embodied in various other mechanical arrangements. Various changes may be made in the construction and arrangement of parts without departing from the spirit of the inventionas will be apparent to those skilled in the art and reference therefore should be had to the appended claims for a limit of the definition of the invention.

What is claimed is:

1. A brake testing device comprising a drum adapted to receive therein a vehicle wheel, said drum being of a diameter only slightly in excess of the wheel diameter, roller supporting means for said drum contacting the outer surface thereof, means independent of the vehicle wheel and the supporting meansto rotate the drum against the resistance of a brake applied to said vehicle wheel, and means for measuring the turning torque. I

2. A brake testing device comprising a drum adapted to receive therein a vehicle wheel, means for rotatably supporting the drum, and means for swivelly carrying said supporting means whereby the drum may be swivelled about a vertical axis;

3. In a brake testing device, a hollow drum having a wheel tread therein, means for rotating said drum about a horizontal axis, and means swivelly mounting said drum to swing about a vertical axis.

4. A brake testing device comprising a rev oluble hollow drum having a wheel tread therein 10 and an open end, a base for said drum, rollers on the base and engaging the drum, and a support for said base and drum, said base and drum n being swivelly mounted on said support for rota- 'tion about a vertical axis. 15 5. A testing device comprising a centrally supported transverse support, a base plate swivelly mounted on each end of the support, a revoluble member having an internal wheel track mounted on each plate, drive means including torque 20 measuring means for rotating said revoiuble members and means'for latching said plates in any one of a number of swivel positions, one of said positions being with the axes of the revoiuble members in a commonwe'rtical plane.

6. A testing device comprising a centrally supported transverse support, a base plate swivelly mounted on each end of the support, means for latching said plates in any one of a number of swivelled positions, a revoiuble member having an internal wheel track mounted on each plate, drive means including torque measuring means for rotating saidrevoluble members, and means for-holding said transverse support against turning movement about its central support.

7. In a brake testing device, a hollow shell having a tread therein, means for rotating said shell about a horizontal axis and. means swivelly /mounting said shell to swing about a vertical axis.

8. In a brake testing device, a hollow cone having a tread therein for receiving a vehicle wheel.

9. A brake testing device comprising a cone I having an internal tread'adapted to receive a sistance of a brake applied to said vehicle wheel,

measuring the turning torque.

and means for MARION M. CUNNINGHAM. 

